The present invention relates to infusion devices for subcutaneous delivery of a medication or a therapeutic fluid by means of an external infusion system and more particularly to an infusion device having releasably connected means for delivery of the medication or the therapeutic fluid from the external infusion system.
Infusion devices are generally known in the art for delivering a medication or a therapeutic fluid to a subcutaneous site in a patient by means of a cannula inserted through the patients skin to the subcutaneous site. Such devices commonly comprise a tubular cannula extending from a housing adapted to receive the desired medication via disconnectable means for suitable connection to further components of the infusion system. The possibility of disconnecting the infusion set from the further parts of the infusion system is provided in order to improve the user comfort. The user is enabled to perform activities which do not allow the presence of a pump or the like, or which are hindered by the presence of a pump or the like. In the disconnected state only a part of the infusion set is worn by the patient. This allows for increased mobility. In order to provide such disconnectable means and still maintain a fluid-tight sealing towards the interior of the housing and the tubular cannula that prevents contamination of the infusion site, such devices are commonly provided with a self-sealing penetrable septum on either the housing or the disconnectable part and a hollow needle on the other part adapted to penetrate the septum. Upon withdrawal of the needle from the septum this provides a fluid-tight sealing towards the interior of the housing. The septum and the needle further provides a fluid-tight sealing between the housing and the connector means when medication or therapeutic fluid is delivered to the patient from the external infusion system. Subcutaneous infusion devices of this generally known type are known from e.g. U.S. Pat. No. 5,522,803 to Teissen-Simony and U.S. Pat. No. 5,545,143 to Fischell.
Due to the relatively small dimensions of such devices and due to the acute insertion angle in relation the skin surface the assembling of the housing and the connector is difficult as the fingers of the user get into close contact with the skin at the insertion site.
For these reasons there is a need for improvements in the infusion devices of the type mentioned in the foregoing, and particularly with respect to providing an infusion device which has improved properties of use and more particularly to an infusion device where the connector in a significant easier manner can be mounted on the housing of the infusion device. The infusion device according to the invention remedies the above mentioned disadvantages and provides further advantages which will become apparent from the following description.